Wear-compensating bolt



1,627,4o y 3 v 1927' G. c. MONCKMELER WEAR COMPENSATING BOLT Filed Oct. 19, l 925 2 Sheets-Sheet 1 1927. May 3 G. c. MONCKMEIER WEAR COMFENSATING BOLT Filed Oct. 19, 1925 2 sheets-sheot 2 ?atentati May 3, 1927.

eus'rav c, rooi'i, or mos, owa.

wu-qonsarme mm.

Application e October ag-'ma Serial xo. sam;

The invention relates to bolts of the type' in which the nut is automatically advanced on the bolt by a spring as wear occurs between the parts clam d by the bolt.

The object of the nvention is to provde an im roved wear com nsating bolt which lke t e bolt forming t e sub'ect matter o my earlier application ria No. 713,151 filed' May 14, 1924, now atent No. 1,585,- o 309, dated May 18, 1926, is adapted to compensate, not only for shrinkage between the parts elamped, but for' temporary limited expansion between the parts, such as oecurs when a. journal beats in service, and when ll an out-of-round journal rotates both before and after becoming heated.

The bolt of the'invention is characterzed by several particularly advantageous features. The -compensating spring of the bolt 'is compalctly housed, and the cup which encases the spring serves as -an anchorage for one end of the same. The toque thus im posed on the cup bythe spring .s transmitted independently of the bolt to one *of the parts clanped by the same. The threads of the bolt are set at a much eaterhelix angle than the threads of or inary bolts, which arrangement 'permits amaterial reduction in the clampng pressure exerted by the nut without necessitating a sacrifice in the strength and durability of. the spring, and also permits the nut to be advanced by the spring a substantial distance axially ofthe bolt without fully exhaustin the tension 4 stored up in the spring. The s' ank of the bolt is reduced in diameter where it passes through the movable element of the part-s clamped together, in order to ive such element freedom of movement wixout destroying the fixed relation which should exist between the bolt and the other element. Each of' the above mentioned features marks the bolt ofthe invention as a distinct' improvement over the devices which others have 46 heretofore developed in attempts to solve the problem of wear compensaton.

While the foregoing statements are indicative of the nature of the invention, other objects and advantages will be evident to those skilled in the art upon a full comprehension of the novel Construction, arrangenot intende the `rod as 'mentand nanner of operation of the bolt of the invention.

`In order that the invention may readily understood, several slightly difiering struc tural embodiments of the same are herein illustrated and described. It should be undertood, however, that the invention is not lmted to the recise details of construction emtployed n t e resentation of those em bo iments, wsuc details are used merely for the pur ose of exemplification, and are] appended claims. r

of its comprehensive scope as defined by the In the accompanymg drawings I to restrict the invention short 'Fig. la side' view of a connecting rod of an internal combustion motor, showing invention;

Fig. 2 -is a different side view of the rod; Fig. 3 is a partially sectioned View of that portion of the rod with which the bolts are, associated; Fig. 4 is a sectional view taken on the line 4-4ofFig.3;-

Fig. 5 is asetional view taken on the line 5-5 of Fig. 3; o

Fig. 6 is a sectional view taken on the line 6-6 of Fig. 3;

Fi 12 is aside view of the Washer shown 13 isa top-plan. view of the Washer; Fg. 14 is a sectional view showing another 'modification equipped with the bolts 'of the Fg. 7 is a sectional view'corresponding Fig. 15 is a sectional view taken onthe line 15--15 of Fig 14; and

Fig. 16 is a view showing' the threads of the bolt of the iivention in comparison with the threads of' an ordinarybolt.

The bolt of the invention obviously has on the front end of the nut, and a centrally ture 22- in t a wide range' of use, but as it is especially well Suite-d for application to the bearngs in internal combustion motors, where wear is constantly occurring and access to the' wearing parts cannot be easily had, the bolt is heren exemplified in such specfic association.

,The drawings show a typical connectng rod bearing assembly, conssting of a connecting rod 10, a hearing cap 11, acrank shaft journal 12 encompassed by complementary ortions of the rod and cap, two semcylin rical bearings 13 interposed betwe n such portions and the journal, and two bolts* 14 adjustably clam ing such portions. Each of the bolts 14 em odes the invention.

I The bolt 14, in that form of the invention shown in Fi s. 1 to 6 inclusive, has screwed thereon a tu ular nut 15. An undulate reaction spring 16 is compressed between the nut- 15 and the bearing cap 11* in an annular groove 17 provided in the front end of the nut, and a helical compensating spring 18 s tensioned about the tubular portion 19 of the nut. An annular flange 20 is provided apertured cup 21 fits over the rear end of the nut and extends forwardly to the flan upon which it is rotatably positioned. T e spring 18 is anchored at its front end to the nut 15 b being hooked through an aperhe fi'ange 20 and is anchored at its rear end to the cup 21 by being hooked through any one of several circumferentially spaced apertures 23 in the side of the cup.

The edges of the aperture 22 in the flange 20 of the nut are preferably rounded of?, as shown, to prevent the spring from wearing thereon. The cup 21 is held against rotation 'in a direction which would unwind the spring by a forwardly extending projection 24 at one side of the cup which serves to abut tangentially of the same against an abrupt shoulder 25 on the hearing cap 11. The cup is prevented from movng rearwardly on the nut into a osition out ot engagement with the shoul er on the cap 1 by a split ring 26 which is removably seated the i same from becoming accidentally unhooked.` The apertures other than the one in which the end of the sprin is positioned may be closed by the associate tongues, thus meam further increasing the efl'ectiveness of the cup as a 'casing for the spring.

v The wear compensatin bolts heretofore produced have exerted c amping pressures of from 15 to 20 pounds, notwithstanding the fact 'that such high pressures are oftentimes extremely undesirable. Various attempts have been made to obtain lower clamping pressure by the obvious method of lowering the tension in the spring, but it was foundthat if the spring was wound a less amount the tension would become exhausted before the nut was advanced very far, while if a lighter spring was Substituted itwould not have sufiicient durability. The bolt of the invention, as distinguished from the bolts of the prior art, is capable of roducing a clamping pressure as low as desred without in any way sacrificing durability or efiiciency of operation. Pressures as low as 2 pounds have been obtained. The threads of the bolt are materially diierent from those of any bolt heretofore produced. for the same general purpose. lt will be observed in .Fig. 16,' where the threads of the bolt of the invention are shown in comfill parison with those of an ordinary bolt 29,

that the threads are multiple and arranged in such a way as to increase greatly the helix angle of the same. According to standard specifications, an ordinar inch `li -thread bolt has from 16 to 24; treads to the inch, and 'hasa lead (which is the distance a thread advances axially in one turn) for each thread equal to the pitch (which is the distance between a point on one thread and a corresponding point on the next thread), giving a 'relative-ly fiat helix angle; while a eg inch V-thread bolt constructed in accordance with the invention and having about the same number of threads to the inch will have a lead from 3 to 6 times greater than the pitch, giving a relatively steep helix' angle. When the nut on the ordinary bolt is turned a complete revoluton, it will only advance on the bolt` from to /8 of an inch, but when the nut on the bolt of the invention is turned a similar amount, it will advance anywhere from to of an inch.` As a result, the leverage which the spring xerts' through the nut is cut down, and the pressure exerted by the nut against the hearing cap is as a consequence substantially decreased without resorting to the employment of a lighter and less durable spring. Furthermore, the nut will take up a much greater amount of wear between the parts clamped without materially exhausting the tension stored up in the spring.

The shunk of the bolt is reduced slightly in diameter from a point 30 just above the bearng `cap 11 to the lower end of the shank, and fits tightly in the connecting red aperture 31 and loosely in the hearing cap lOO ` t aperture 32. The bearin cap as a result will not bind on the shan of the bolt, and is capable of being moved freely along the shank by the nut 15. The head of the bolt has a flattened side 33 which fits in the usual manner a ainst a shoulder on the connectng rod and olds the bolt against rotation in either direction.

The bolt may be installed in a connecting rod bearing assembly in the following manner:

The bolt is inserted through the aligned apertures 31 and 32 in the connecting rod 10 and bearin cap 11, the reaction spring 16 is seated in te groove 17 in the front end of the nut 15, and the nut is screwed upwardly on the shank of the bolt a s'uflicient distance to place the cap 11' in the desired position relative to the rod 10. The cup 21 is shifted downwardly on the nut 15, the split rin 26 having first been removed, and is rotate to the right to wind up the spring 18. When the spring 18 has received sufllcient tension, the cup 21 is-shifted u wardly again on the nut 15 and is permitte to turn to the left until the -projection 24 on the cup looks with the shoulder 25 on the bearcap. The split ring 26 is then reinserted n the groove 27. It will be understood, of course, that as wear occurs in the bearing, the spring 18 will cause the nut 15 to advance on the bolt, and that conditions such as expansion of the journal 12 under heating will be taken care of by the limited retraction of the cap 11 as permitted by the spring 16.

In Fig. 7 is shown a slightly modified form of the invention in which the nut 34 on the bolt is shorter, and the cup 35 extends beyond the rear end of the nut and has a polygonal aperture in the bottom which seats over a polygonal portion 36 of the bolt. A flange 34' is positioned at the rear end of the nut to prevent the spring from slipping-rearwardly from the nut onto the threads of the bolt. The cup 35 does not have any projection which' interlocks with a shoulder on the bearin ca 11, as the portion 36 of the bolt ho ds t eicup against rotation. The cup is maintained in engagement with the portion 36 b ,means of a removable cotter pin 37 whic passes through a cylindrical portion 38 at the extreme end of the bolt. This particular feature is covered in my' copendingpplication, Serial No. 135,167, filed Septem r 13, 1926. 4

In Figs. 8, 9 and 10 are shown other forms of the invention which are in many respects quite similar to the form shown in Fig. 7. In Fig. 8 a short coil spring 39 is used in place of the undulate spring 16, and the spring 39 closely encircles a tubular projeetion 40 on the front end of the nut. In Fig. 9 the undlate spring 16,' instead of being positioned in the annular groove 17 in tion in fixed relation to the bolt. The portions of the nut and cap which are adapted to abut against each other when the sprng 43 yields have interposed therebetween a hardened Washer 45 which prevents the otherwise exposed 'edge of the aperture 32 in the cap from becoming deforned under the hammering .action of the nut.

In Figs. 11 to 13 inclusive is shown another modified form of the invention in which a Washer 46 having a polygonal aperture fits over a polygonal portion of the bolt. The Washer is held in place by a cotter pin which passes through the end of the bolt, and the cup shown in the eviously described forms is dispensed wit The nut has a cyhndrical portion 47 about which most of the coils of the spring 48 are wound, and the Washer 46 has a short cylindricalportion .49 about which the lower coil of thesprin is guided. -The cylindrical portion 49 o the' Washer is preferably provided with a helical roove 50 for positoning the lower coil of t e spring properly, and the flat porwhich the lower end of the spring is hooked.

In Figs. 14 and 15 is shown still another modified form of the invention which difl'ers from that shown in Fig. 7 only in the manner in which the cup 51 is locked against rotation after it has been turned to the right to wind up the associated spring. The centrally apertured portion of the cup is provided with a plurality'of in'wardly extending tongues 52 which are cut on a radius less than the crest of the threads on the bolt, and the threaded end of the. bolt is provided with longitudinally extending Slots 53 in the threads through which the tongues 52 may slide after the cup has been rotated sufli ciently and is being moved upwardly over the end of the bolt. It will be understood that when this Construction, which resembles in some respects a breach lock, is employed the cup may be efl'ectively locked against rotation at any point on the bolt by merely permittng the cup to turn back a part of one revolution whereupon 'the tongues 52 will tightly wedge into those portions of the angularly disposed threads bordering upon the Slots 53.

I claim: e

1. In a device of the class described, a bolt, atubular nut having an annular flange adj ation of the Washer has an aperture through cent one end of the same, a coil spring encircling the tubular portion of the nut for automatically advancng the nut on the bolt, and a centrally apertured sprin -encasing supet cylindrical form positone with the cyhndrical side of the same rotatably mounted on the flange of 'the nut and with the apertured bottom of the same rotatably mounted on the tubular. ortion.

2. Ina devce of the class described, a bolt, a nut, a coil spring for automatically advancing the nut on the bolt, a connection between one end of the spring and the nut, a spring-encasing menber, a connection between the other end of the spring and the member, and means for locking the member against rotation relative to the bolt.

3. In a device of the class described, a bolt, a nut, a coil spring for automatically advancing the nut on the bolt, a connection between one end of the spring and the nut, a spring-encasing member, a connection between the other end of the spring and the member, and means on the member coactable with one of the arts adapted to be clamped by the bolt f or ocking the member aganst rotation relative to the same. u

4. In a device of the class described, a bolt, a nut, a coil spring for automatically advancing the nut on the bolt, a connection between one end of the spring and the nut, and a sheet metal spring-encasing member having an outwardly displaceable ton e punched in the side of the same to provi e a shielded aperture through which the other end of the spring may be hooked.

5. In a device of the class described, a bolt, a nut, a coil spring for automatically advancing the nut on the bolt, a connection between one end of the spring and the nut, and a sheet metal spring-encasing member having a plurality of outwardly'displace able tongues punched in the side at intervals circumferentially of the same to provide at any desired oe of *the tongues a shielded aperture through which theother end of the spring ma be hooked.

6. n a evice of the class described, a bolt, a nut, a coil spring for automatically advancing the nut on the bolt, a connection between 'one end of the spring and the nut, a sheet metal sprin -encasing member, a connection between t e other end of the spring and the member, and a projection on the member for lockng the same against rotation in one direction by abutting tangentially of the member against a shoulder on one lthe parts adaptedjo be clamped by the 7. Ina device of the class described, a bolt, a tubular nut, a coil spring encirclmg the nut for automatically advancing the nut on the bolt, a centrally apertured spring-encasing cup seated over the nut, and a split ring removably seated in an annular groove in the nut at one side of the cup for holding the latter in position relative to the nut.

8. In a device of the class described, a bolt adapted to pass through both a relatively stationary member and a relatively movable member, a nut adapted to a ply pressure to the movable member, an a spring for automatically advancing the nut on the bolt, the portion of the bolt adapted to pass through the movable member beng reduced in diameter whereby to faeilitate movement of such member axially of the bolt under the pressure of the nut.

9. In a device of the class described, a bolt, a nut, and a coil spring for automatically advancin the nut on the bolt, the threading on the bo t and nut being multiple and having a lead which is from three to sin times thepitch, for the purpose set forth.

In testimony whereof I have hereunto subscribed my ne.

enemy c. moncmmnn. 

